From 8142db4f2792717837b97e219e5f5203dde17abb Mon Sep 17 00:00:00 2001 From: Eric Van Hensbergen Date: Sat, 17 Dec 2022 17:19:34 +0000 Subject: [PATCH] fs/9p: allow disable of xattr support on mount xattr creates a lot of additional messages for 9p in the current implementation. This allows users to conditionalize xattr support on 9p mount if they are on a connection with bad latency. Using this flag is also useful when debugging other aspects of 9p as it reduces the noise in the trace files. Signed-off-by: Eric Van Hensbergen Reviewed-by: Dominique Martinet --- Documentation/filesystems/9p.rst | 2 ++ fs/9p/v9fs.c | 9 ++++++++- fs/9p/v9fs.h | 3 ++- fs/9p/vfs_super.c | 3 ++- 4 files changed, 14 insertions(+), 3 deletions(-) diff --git a/Documentation/filesystems/9p.rst b/Documentation/filesystems/9p.rst index 7b5964bc88652d..0e800b8f73cc3a 100644 --- a/Documentation/filesystems/9p.rst +++ b/Documentation/filesystems/9p.rst @@ -137,6 +137,8 @@ Options This can be used to share devices/named pipes/sockets between hosts. This functionality will be expanded in later versions. + noxattr do not offer xattr functions on this mount. + access there are four access modes. user if a user tries to access a file on v9fs diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c index a46bf9121f11a8..f8e952c013f905 100644 --- a/fs/9p/v9fs.c +++ b/fs/9p/v9fs.c @@ -38,7 +38,7 @@ enum { /* String options */ Opt_uname, Opt_remotename, Opt_cache, Opt_cachetag, /* Options that take no arguments */ - Opt_nodevmap, + Opt_nodevmap, Opt_noxattr, /* Access options */ Opt_access, Opt_posixacl, /* Lock timeout option */ @@ -55,6 +55,7 @@ static const match_table_t tokens = { {Opt_uname, "uname=%s"}, {Opt_remotename, "aname=%s"}, {Opt_nodevmap, "nodevmap"}, + {Opt_noxattr, "noxattr"}, {Opt_cache, "cache=%s"}, {Opt_cachetag, "cachetag=%s"}, {Opt_access, "access=%s"}, @@ -149,6 +150,9 @@ int v9fs_show_options(struct seq_file *m, struct dentry *root) if (v9ses->flags & V9FS_POSIX_ACL) seq_puts(m, ",posixacl"); + if (v9ses->flags & V9FS_NO_XATTR) + seq_puts(m, ",noxattr"); + return p9_show_client_options(m, v9ses->clnt); } @@ -269,6 +273,9 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts) case Opt_nodevmap: v9ses->nodev = 1; break; + case Opt_noxattr: + v9ses->flags |= V9FS_NO_XATTR; + break; case Opt_cachetag: #ifdef CONFIG_9P_FSCACHE kfree(v9ses->cachetag); diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h index e5d41804b3cd1c..8cd63782a25c18 100644 --- a/fs/9p/v9fs.h +++ b/fs/9p/v9fs.h @@ -36,7 +36,8 @@ enum p9_session_flags { V9FS_ACCESS_SINGLE = 0x04, V9FS_ACCESS_USER = 0x08, V9FS_ACCESS_CLIENT = 0x10, - V9FS_POSIX_ACL = 0x20 + V9FS_POSIX_ACL = 0x20, + V9FS_NO_XATTR = 0x40 }; /* possible values of ->cache */ diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c index 65d96fa94ba228..5fc6a945bfff49 100644 --- a/fs/9p/vfs_super.c +++ b/fs/9p/vfs_super.c @@ -64,7 +64,8 @@ v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, sb->s_magic = V9FS_MAGIC; if (v9fs_proto_dotl(v9ses)) { sb->s_op = &v9fs_super_ops_dotl; - sb->s_xattr = v9fs_xattr_handlers; + if (!(v9ses->flags & V9FS_NO_XATTR)) + sb->s_xattr = v9fs_xattr_handlers; } else { sb->s_op = &v9fs_super_ops; sb->s_time_max = U32_MAX;